AbstractIn 1910–1911, T. S. Eliot studied Henri Bergson’s books and attended his lectures in Paris. Initially fascinated by Bergson’s ideas, Eliot experienced what he called a “conversion” to Bergsonism, but as shown by poetry and prose written during and after the lectures, he quickly became disillusioned. This essay discusses the Bergsonian claims that intrigued Eliot in the winter of 1910–1911, the skepticism revealed in “Rhapsody on a Windy Night” and other poems dated March 1911, and the critique presented in a previously unpublished lecture for the Harvard Philosophical Club in December 1913. Eliot concludes that dualism is intractable, for the material and moral realms cannot be merged. This conclusion, formative in his intellectual development, is illuminating in regard to his poetry and criticism. It is also suggestive in regard to the more general modernist motif regarding the difficulty of making connections.